反应详情

A solution of 8.2 g of (unpurified, about 90% pure) 2-cyano-3-ethoxyacrylic acid N-isopropyl-N-(3-trifluoromethylphenyl)amide (compound IV: R4 =CH(CH3)2 ; R5, R6 =H; R7 =C2H5) in 20 ml of abs. DME was added dropwise to a suspension of 3.91 g (25 mmol) of 1-amidino-4,4-dimethyl-2-oxoimidazolidine in 16 ml of abs. DME at 20°, and the mixture was stirred at 22°-24° for 4.5 hours. The mixture was then evaporated in vacuo at a maximum bath temperature of 25°. The oily residue was taken up in 250 ml of ether and extracted six times with 25 ml of water each time. The etherial solution was then dried over MgSO4, filtered and evaporated in vacuo (<26°). The residue (12.7 g) was partially crystalline. The latter was taken up in 40 ml of ether, 2 ml of pentane were added, the mixture was left to stand at 4°-6° for 2 days and subsequently the crystals were filtered off with suction. Drying (over P4O10 at 20°-24°, 6-8 mbar, 48 hours) resulted in 5.12 g (=47% yield) of TLC-pure compound II (R1, R2 =CH3 ; R3, R5, R6 =H; R4 =CH(CH3)2), melting point 121°-122° C.

1. customThe mixture was then evaporated in vacuo at a maximum bath temperature of 25°
2. extractionextracted six times with 25 ml of water each time
3. dry with materialThe etherial solution was then dried over MgSO4
4. filtrationfiltered
5. customevaporated in vacuo (<26°)
6. addition2 ml of pentane were added
7. waitthe mixture was left
8. filtrationsubsequently the crystals were filtered off with suction
9. dry with materialDrying (over P4O10 at 20°-24°, 6-8 mbar, 48 hours)